Make invariant for lazy ByteString visible in haddock

[Bodigrim]

bytestring/Data/ByteString/Lazy/Internal.hs

Lines 81 to 88 in c967aca

	data ByteString = Empty | Chunk {-# UNPACK #-} !S.StrictByteString ByteString
	-- INVARIANT: The S.StrictByteString field of any Chunk is not empty.
	-- (See also the 'invariant' and 'checkInvariant' functions.)
	-- To make testing of this invariant convenient, we add an
	-- assertion to that effect when the HS_BYTESTRING_ASSERTIONS
	-- preprocessor macro is defined, by renaming the actual constructor
	-- and providing a pattern synonym that does the checking:

This should really be a haddock-visible documentation for Chunk constructor instead of source-only comment.